Present methods of pneumatically controlling the movements of actuators in small missiles have involved using either a single solenoid valve operating in an open center mode or a pair of solenoid valves operating in a closed center mode. The open center mode is typified by a constant gas flow that is either used to power the actuator or discarded overboard. The closed center mode, on the other hand, only uses the pressurized gas when motion of the actuator is required, thereby minimizing the amount of stored gas needed to operate the actuator or allowing a much longer run time. A major trade-off between these two methods is that a single solenoid valve operating in open center mode is less costly than a pair of solenoid valves operating in a closed center mode, but makes much less efficient usage of a fixed volume of stored high pressure gas that is used by both methods.
There is a need for a single valve that will operate as a closed center valve that is less costly than two simple two-way solenoid valves, and requires a less expensive electrical controller and less electrical power requirements to operate than a pair of solenoid valves. Also, there is a need for such a closed center valve that will operate in a closed center mode for example at frequencies above 30 cycles per second and at temperatures ranging from -65.degree. F. to 450.degree. F. Furthermore, there is a need for such a closed center valve that has a relatively long operational life and a storage life in excess of ten years.